The present invention relates to a composite material made up from reinforcing fibers embedded in a matrix of metal, and more particularly relates to such a composite material utilizing alumina-silica type short fiber material as the reinforcing fiber material, and aluminum alloy as the matrix metal, i.e. to an alumina-silica short fiber reinforced aluminum alloy.
Further, the present inventors wish hereby to attract the attention of the examining authorities to copending patent application Ser. Nos. 868,541; 868,542; 868,750; 895,811; 901,196; 911,880; and 001,924 which may be considered to be material to the examination of the present patent application.
As fiber reinforced aluminum alloys related to the present invention, there have been disclosed in the following U.S. patent applications filed by an Applicant the same as the Applicant of the parent Japanese patent applications of which Convention priority is being claimed for the present patent application--Ser. Nos. (1) 868,542; (2) 868,750; and (3) 868,541--respectively: (1) a composite material including silicon carbide short fibers in a matrix of aluminum alloy having a copper content of from approximately 2% to approximately 6%, a magnesium content of from approximately 2% to approximately 4%, and remainder substantially aluminum, with the volume proportion of said silicon carbide short fibers being from approximately 5% to approximately 50%; (2) a composite material including alumina short fibers in a matrix of aluminum alloy having a copper content of from approximately 2% to approximately 6%, a magnesium content of from approximately 0.5% to approximately 4%, and remainder substantially aluminum, with the volume proportion of alumina short fibers being from approximately 5% to approximately 50%, and (3) a composite material including silicon carbide short fibers in a matrix of aluminum alloy having a copper content of from approximately 2% to 6%, a magnesium content of from approximately 0% to approximately 2%, and remainder substantially aluminum, with the volume proportion of said silicon carbide short fibers being from approximately 5% to approximately 50%. However, it is not hereby intended to admit any of the above identified documents as prior art to the present patent application except to the extent in any case mandated by applicable law.
In the prior art, the following aluminum alloys of the cast type and of the wrought type have been utilized as matrix metal for a composite material:
Cast type aluminum alloys
JIS standard AC8A (from about 0.8% to about 1.3% Cu, from about 11.0% to about 13.0% Si, from about 0.7% to about 1.3% Mg, from about 0.8% to about 1.5% Ni, remainder substantially Al)
JIS standard AC8B (from about 2.0% to about 4.0% Cu, from about 8.5% to about 10.5% Si, from about 0.5% to about 1.5% Mg, from about 0.1% to about 1% Ni, remainder substantially Al)
JIS standard AC4C (Not more than about 0.25% Cu, from about 6.5% to about 7.5% Si, from about 0.25% to about 0.45% Mg, remainder substantially Al)
AA standard A201 (from about 4% to about 5% Cu, from about 0.2% to about 0.4% Mn, from about 0.15% to about 0.35% Mg, from about 0.15% to about 0.35% Ti, remainder substantially Al)
AA standard A356 (from about 6.5% to about 7.5% Si, from about 0.25% to about 0.45% Mg, not more than about 0.2% Fe, not more than about 0.2% Cu, remainder substantially Al)
Al--from about 2% to about 3% Li alloy (DuPont).
Wrought type aluminum alloys
JIS standard 6061 (from about 0.4% to about 0.8% Si, from about 0.15% to about 0.4% Cu, from about 0.8% to about 1.2% Mg, from about 0.04% to about 0.35% Cr, remainder substantially Al)
JIS standard 5056 (not more than about 0.3% Si, not more than about 0.4% Fe, not more than about 0.1% Cu, from about 0.05% to about 0.2% Mn, from about 4.5% to about 5.6% Mg, from about 0.05% to about 0.2% Cr, not more than about 0.1% Zn, remainder substantially Al)
JIS standard 7075 (not more than about 0.4% Si, not more than about 0.5% Fe, from about 1.2% to about 2.0% Cu, not more than about 0.3% Mn, from about 2.1% to about 2.9% Mg, from about 0.18% to about 0.28% Cr, from about 5.1% to about 6.1% Zn, about 0.2% Ti, remainder substantially Al).
Previous research relating to composite materials incorporating aluminum alloys as their matrix metals has generally been carried out from the point of view and with the object of improving the strength and so forth of existing aluminum alloys without changing their composition, and therefore these aluminum alloys conventionally used in the manufacture of such prior art composite materials have not necessarily been of the optimum composition in relation to the type of reinforcing fibers utilized therewith to form a composite material, and therefore, in the case of using one or the other of such conventional above mentioned aluminum alloys as the matrix metal for a composite material, the optimization of the mechanical characteristics, and particularly of the strength, of the composite material using such an aluminum alloy as matrix metal has not heretofore been satisfactorily attained.